body {
  margin: 0;
  padding: 0;
}

.game {
  width: 800px;
  height: 600px;
  border: 2px solid;
  margin: 0 auto;
  position: relative;
  overflow: hidden;
}

.game .sky {
  background: url("./img/sky.png");
  height: 100%;
  width: 200%;
  position: absolute;
  top: 0;
  left: 0;
}

.game .land {
  background: url("./img/land.png");
  height: 112px;
  width: 200%;
  position: absolute;
  left: 0;
  bottom: 0;
}

.game .bird {
  background: url("./img/bird.png");
  position: absolute;
  width: 33px;
  height: 26px;
  left: 150px;
  top: 150px;
}

.game .bird.swing1 {
  background-position: -8px -10px;
}

.game .bird.swing2 {
  background-position: -60px -10px;
}

.game .bird.swing3 {
  background-position: -113px -10px;
}

.game .over {
  color: black;
  z-index: 999;
  position: absolute;
  top: 40%;
  left: 50%;
  transform: translate(-50%, -50%);
  text-align: center;
}

.pipe {
  position: absolute;
  height: 150px;
  width: 60px;
  left: 500px;
}

.pipe.up {
  background: url("./img/pipeDown.png");
  top: 0;
  background-position: bottom;
}

.pipe.down {
  background: url("./img/pipeUp.png");
  bottom: 112px;
}

.prop-opacity {
  position: absolute;
  width: 30px;
  height: 30px;
  left: 300px;
  background: yellow;
  border-radius: 50%; /* 修改为圆形 */
}
.prop-protect {
  position: absolute;
  width: 30px;
  height: 30px;
  left: 300px;
  background: green;
  border-radius: 50%; /* 修改为圆形 */
}
.prop-sprint {
  position: absolute;
  width: 30px;
  height: 30px;
  left: 300px;
  background: red;
  border-radius: 50%; /* 修改为圆形 */
}

.info {
  text-align: center;
}

.game .score {
  position: absolute;
  left: 15px;
  top: 5px;
  color: red;
  font-size: 32px;
  font-weight: bold;
  z-index: 999;
}

.game .start {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 1000;
  padding: 10px 20px;
  font-size: 16px;
  cursor: pointer;
  background-color: #4caf50;
  color: white;
  border: none;
  border-radius: 5px;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

@media (max-width: 600px) {
  .info {
    display: none;
  }
  .difficulty {
    display: none;
  }
  .game {
    width: 100%;
    height: 100vh;
  }
  .sky,
  .land,
  .bird,
  .score,
  .over {
    width: 100%;
  }
}
